Why sdkmanager won't get updated?

Question

I am trying to use flutter and flutter doctor gives me an error:

Android toolchain - develop for Android devices (Android SDK version 29.0.0)
    ✗ Android license status unknown.
      Try re-installing or updating your Android SDK Manager.
      See https://developer.android.com/studio/#downloads or visit
      https://flutter.dev/setup/#android-setup for detailed instructions.

I tried multiple solutions and I updated my sdkmanager to:

DEFAULT_JVM_OPTS='"-Dcom.android.sdklib.toolsdir=$APP_HOME" -XX:+IgnoreUnrecognizedVMOptions --add-modules java.se.ee'

and when I did /Users/bsikriwal/Library/Android/sdk/tools/bin/sdkmanager --update I got a new error:

Error occurred during initialization of boot layer
java.lang.module.FindException: Module java.se.ee not found

Any help?

System:
MacOS Mojave 10.14.5.
Java version "12.0.1" 2019-04-16.
Java(TM) SE Runtime Environment (build 12.0.1+12).
Java HotSpot(TM) 64-Bit Server VM (build 12.0.1+12, mixed mode, sharing)